Work on reviewing regulations to reduce emissions of air pollutants from ships was high on the agenda when the IMO Sub-Committee on Bulk Liquids and Gases (BLG) met for its 11th session from 16-20 April 2007. It followed on from an intersessional meeting of the BLG Working Group on Air Pollution, which took place from 13 to 17 November 2006, in Oslo, Norway, to develop the necessary MARPOL amendments. The Working Group on Air Pollution was reconvened during the current session, chaired by Mr. Bryan Wood-Thomas (United States), to progress the work in hand. The Working Group reviewed the proposed three-tier system approach for NOx emission limits applicable to new engines…